"You do anything for kids, and it's rewarding," Brady, who voices the rabbit Clover, told The Hollywood Reporter afterward. "It's nice to be able to make a child happy and to make kids feel good and help them retain that innocence for as long as they can."

For his part, Gunn said he's developed an entirely fan base through his role as royal servant Baileywick, whose appearance was modeled on the Project Runway mentor.

"I'll be on the subway and someone will say hello to me, and I'll say hello, and a little kid will look up at me and ask, 'Baileywick?'" Gunn told THR. "I have a lot of kids who live in my building, and when I'm in the elevator with them, they're in awe. It's a response I've never had from Project Runway, and it's really quite thrilling."

Gunn said it was a no-brainer to sign on to the series.

"I saw the script for the movie, which came out last November, and I loved it," he said. "I thought, 'This is feel-good with little morality tales, and this is what kids need. There is too much garbage on television, and if I were a parent I would want my kids to be watching this, so I'm on board. I just didn't know what an incredible phenomenon it would become."

Gunn revealed that his favorite episode so far has been one in which Sofia (voiced by Modern Family's Ariel Winter) teaches the villagers that the trolls living under a bridge shouldn't be treated differently just because of their looks.

The show was recently greenlighted for a second season, and Brady gave a preview of what fans can expect.

"There will be a lot of music," he said. "Clover gets into even more trouble, and you'll get to see the relationship grow between Sofia and the animals that only she can talk to. And there will be more singing."

Asked if he might sing at some point, Gunn is emphatic: "Nooooo." But he adds that he did a voice-over for Disney Productions to be used in musical shows at Disney's theme parks.

"I said to the director, 'I would like to do this like Rex Harrison in My Fair Lady,' which is speak-singing," he said. "But in terms of being able to hold a tune? No. And he said, 'That won't be expected of you,' so it was a big relief."

At the D23 Expo, Brady and Gunn greeted fans and read from two soon-to-be-released storybooks from Disney Publishing, including Sofia the First: The Floating Palace, based on the upcoming Disney Junior fall primetime TV special of the same name, which Gunn called "fantastic. It's a lot of fun."